Let's start by analysing the two compounds.
Stano-drol converts into stanolone, D-plex converts into methyl-stanolone, wich makes it more powerfull compared to Stano-drol mg per mg, though it has the methylation issue, so it's kind of comparing oranges and lemons, they're similar in much aspects but they diverge in some degree. But one this is for sure: the two compounds are dry componds and by staking them with P-mag (wich is the wet brother of H-drol) doesn't makes much sense.
Oh and one more thing, keep in mind that D-plex can/will increase agressiveness, so if it was my case since I've a very short temper it would be like stacking a flame to gun powder. As for Stano-drol it seems much mild in that department (or in any other, since it has been compared to 11-oxo in terms of mildness)